Conventional aircraft typically are constructed with retractable landing gear having a stowed position, in which the landing gear wheels are held in wells within the airplane structure to reduce aerodynamic drag during flight, and a deployed position, in which the landing gear wheels are extended to engage the ground surface during takeoff, landing, and ground operations. In addition, the fuselage of such conventional aircraft are constructed with landing gear doors that can cover the stowed landing gear during flight, and cover the landing gear wells while the aircraft is on the ground. To reduce structural stress, fuel consumption, and noise during flight, and to facilitate gear well protection and maintenance while the aircraft is on the ground, it is desirable to dispose and maintain a landing gear door in a proper position, for example, with respect to the surface of an aircraft fuselage, of another landing gear door, or of the landing gear. Frequently, positioning may be made relative to multiple reference surfaces.
To achieve proper mating of the exterior surface of a landing gear door relative to adjacent exterior surfaces of the aircraft within specified tolerances, present initial factory installation and subsequent field maintenance procedures call for full landing gear cycling, that is actuating the landing gear between a stowed position and a fully-deployed position. During cycling, factory or maintenance personnel typically take measurements and provide adjustments to the landing gear door connections to meet an “as designed” positioning specification.
In the case of a main landing gear door, the main landing gear may be fully cycled several times, with the obtained measurements being used subsequently, such as to adjust a tie-rod that may attach the landing gear door to the aircraft at particular locations, or a washer/shim stack-up at another location. Often, after deployed measurements, the pin, washer, and nut installations associated with a particular aircraft attachment point are removed, recalculated, and re-installed; with the landing gear door fit and fair measurements again being taken after the landing gear is actuated to the stowed position. If necessary, these fit and fair measurements are used to make additional iterative adjustments to tie-rods, pins, washers, and nuts, until an acceptable “as designed” fit and fair is achieved. Understandably, such adjustment can be both time consuming and costly.
As a result, there is a need for an apparatus and method by which “as designed” fit and fair positioning can be achieved for aircraft landing gear doors without cycling the landing gear, for example, by allowing adjustment to the landing gear door while the landing gear is stowed.